89540-08-9Relevant academic research and scientific papers
METALLKATALYSIERTE ZERSETZUNG VON 4-DIAZOMETHYL-4H-PYRANEN - EIN NEUER ZUGANG IN DAS OXEPINSYSTEM
Hoffmann, Karl-Ludwig,Regitz, Manfred
, p. 5355 - 5358 (1983)
Electrophilic diazoalkane substitution of lithiated diazomethyl compounds (5) with the pyrylium salt 4 leads to the formation of the hitherto unknow 4-diazomethyl 4H-pyranes 6.Their decomposition with catalytic amounts of μ-allyl palladium chloride (dimer) in benzene is followed by ring enlargement to the oxepines 8, which are not in equilibrium with the valence tautomeric benzene oxides 7.
Carbenes, 30. Metal-catalyzed Decomposition of 4-Diazomethyl-4H-pyrans - a New Access to the Oxepin System
Hoffmann, Karl-Ludwig,Maas, Gerhard,Regitz, Manfred
, p. 3700 - 3713 (2007/10/02)
Electrophilic diazoalkane substitution at the lithiated diazomethyl compounds 5a-d with the pyrylium salt 6 yields the 4-diazomethyl-4H-pyrans 7a-d.Only in the case of 5d competitive attack in the 2-position of the pyrylium salt is observed, leading ultim
